Nick Clegg has challenged UKIP leader Nigel Farage to a public debate on whether the UK should remain in the European Union.

The Liberal Democrat leader said that at least Mr Farage was clear in his position on Europe, while the Tories were split and Labour "lacked the courage of its convictions".

He positioned the Liberal Democrats as the party of "in", saying that it was time for UKIP and the Lib Dems to go toe-to-toe on the issue.

Speaking on his weekly LBC Call Clegg radio programme, he said: "I'll tell you what I'll do. I will challenge Nigel Farage to a public, open debate about whether we should be in or out of the European Union.

"He is the leader of the party of out, I am the leader of the party of in."

Mr Clegg claimed three million jobs in the UK depended on membership of the EU.

Image Caption:Nigel Farage and his party support withdrawal from the EU

"I hope he will take up my challenge to debate, once and for all, publicly, should we be in the European Union - which I believe means that we have more people in work than would otherwise be the case, we keep ourselves safer because we can go after cross-border crime and terrorism, we can look after the environment in a way we can't on our own," he said.

"Or do we do what UKIP wants, which is to pull ourselves out of the European Union and so jeopardise millions of jobs in this country?" he said.

The Liberal Democrats are at risk of losing seats in the European Parliament in the upcoming elections in May - polling has given UKIP a lead over the party.

The party's president, Tim Farron, has warned the Lib Dems' "very presence in the European Parliament could be at stake", according to The Times.

"The next year will be the fight of our lives - to make sure the country knows everything that we have been doing as part of the Coalition," he said

Following Mr Clegg's challenge, a party spokesman added that "the terms and arrangements for any debate would have to be agreed by both sides".

Image Caption:Sky News hosted a leaders' debate ahead of the 2010 General Election

Mr Farage is expected to give his response when he appears on LBC on Friday.

A spokesman said: "Mr Farage would like to thank Mr Clegg for his kind invitation to a debate on the great issue of Britain's membership of the European Union.

"Perhaps he could also let us know whether he has invited David Cameron and Ed Miliband too in order that the British people can see all their main political leaders argue their positions.

"If this challenge means that Mr Clegg is going to restore his backing for an in/out referendum, which he gave before the last election but then withdrew afterwards, then it could be a significant moment in British politics."

David Cameron has made it clear that he does not think Mr Farage should be allowed to take part in televised leadership debates ahead of the 2015 General Election, if agreement is reached for them to take place.

However, Mr Clegg has made clear that he thinks the UKIP leader should be allowed to take part.

The US-style leadership debates were televised in Britain for the first time ahead of the 2010 General Election with broadcasters, including Sky News, hosting the showdowns.